This is akin to going to Google, or more accurately Open Street Map since we want to keep the metaphor, and threatening them with legal action for creating a ma

This is akin to going to Google, or more accurately Open Street Map since we want to keep the metaphor, and threatening them with legal action for creating a map with the address of your house on it and noting that there's a priceless mural which you originally advertised and made publicly available elsewhere. Since people can take the map, find your address on it, and take pictures of the priceless mural, which they can then use to train a monkey to incorporate the style of the mural into other murals that the monkey creates, thus violating your copyright. And the murals that the monkey produces are not copyrightable. But also, yes, in that instance, if it's public and the door's open. Your analogy isn't a good one though. I like mine better, to illustrate the hoops the artist had to jump through.